Pneumatic impact-tool.



G. L. BADGBR.

PNEUMATIC AIMPACT TOOL. APPLICATION FILED JAgI. e, 1906.

UNTED STATES .lPr-XTENT QFFECE,

i PNEUMATIC IMPACT-Toor..

No. 904,827.y

Specification of Letters Patent.

Patented Nov. 24, 1908.

Application tiled January 6, 1906. Serial No. 294,916.

To all ywhom lit may concern:

Be it known that l, Gnome L. Banaan, Citizen ot the United States, residing at Quincy, in the county ot Norfolk, State ot' lvlassachusetts, have invented a certain new and useful Improvement in Pneumatic Imact-Tools ot which the following is a s )eciication, reference heinghad therein to the accompanying drawings.

This invention relates to improvements in pneumatic impact tools.

The principal features ot the present invention relate to an improved 'torni ot' valve for controlling the movements ot" the piston, the valve being quickly actuated, light and strong, and having a large area ot port opening with a comparatively small diameter ot valve and short travel or movement; and a throttle-valve for controlling the initial admission ot motive fluid to the tool, which is operated hy a longitudinal movement olthe grasping-handle, the assembled parts requiring less than the usual length needed tor the grasping-handle and throttle- "alve in tools ot this class.

The controlling-valve is made with bearing surfaces ot different diameters and provided with two annular grooves, one of said grooves being in the small diameter ot the valve and al rays open to' [luid pressure., which acting on the groove walls ot' ditl'erent, areas always tends to press the valve in a forward direction. rlhe other groove is in the larger diameter of the falve and is always open to the atmosphere through ports in the valve-block. lhe construction is ,such that the motivel tluid which might escape from the inlet-port or groove, in the small diameter ot the valve, past the large hearing surface will enter the exhaust groove in the large diameter of the valve and pass through the exhaust-ports in the valvehlock, so that it cannot reach the large area vor pressure surface ot the valve to intierl'ere with the proper operation oi? the valve.

lVith the construction and arrangement ol grooves or ports in the valve and valve-block, the area ot the larger pressure lsurface ot the valve can be made much greater than the ettective area pressing the valve torward, even with `a valve ot con'iparatively small diamleter, so that Whenair is Vadmitted to the larger area it moves the valve backward verv D n n x quickly, thereby increasing the piston speed over that of a slower moving valve.

capacity The diameters oit the valve can he made so that the etlieetive area'tor moving the valve forward will he very slight. The rush of air against the forward wall of the inlet-groove of the'valve always tends to move the valve 't'orwarth and owing to the great: ditterence ot' the opposing pressure areas I obtain a very quick moving valve, which as betere stated may he ot comparatively small diameter having grooves and port areas of large It is obvious that, other things heing equal, a valve with a small diameter is much to he preferred rto a valve of large diameter.

I also provide means whereby the smaller end ot the valve is always open to the atmosphere. I prefer to connect the smaller end ot' the valve-chamber with the atmosphere hy a passage in the retaining-head of the valve-block.

l prefer to make the valve in theifiorm ot a tubular shell closed at one end; it may however he made solid. The tubular construction is used simply to reduce the weight' ot the valve and is not esseiitial to the lu oader scope ol the invention.

ln some instances it is desirable to provide port openings ot very large area, especially the port connecting with the rear end ot the pison-clunnher. To accomplish this it has heretofore heen necessary to use valves ot comparatively large diameter provided with inlet or exhaust ports through the interior ot the valve.y or through the walls thereof. lhe latter construction greatly weakens the val ve which is liable to he broken h v the constant lnnnlneringaction to which the valve is suhjcciotfl when in operation.

l al'n enahted to provide the greatest possihlo area otl valve port opening, for supplying and exhausting the inotivctluid to the rear end olE the piston-chamber with a given diameter and mo\ ement ol the valve. lVhen the tuhul'ar Ylorin ot valve is employed I can, it desired, connect the interior ot' the valve ov a .small hole with the annular exhaust groove on the exterior ot the valve, in order to prevent any accumulation of fluid pressure on the small end ot the valve which might. leak h v the joints or bearing surfaces. ln this case it will not he necessary to con'- nect the rear end o't the val ve-chamber with the atmosphere exteriorly to Ithe valve.

It is desirable in some instances that the operation ot thc tl'irottle-valve he controlled by theV action of pressing tbe tool to tbe Work. 'With this object in view l provide a gras ing-liandle'inounted on the reteinirgneat. and longitudinally niovable tlier-eoi` andadapted to engage tbe throttle-valve ,te unseat the latter wlienthe graspinglmndlet is pushed forward. l arrange tlie throttle ve.

ve transversely to tlie bore of tbe piston.

clieinber in order tosliorten the length of tbe-tool. l provide the Working Cylinder in the present instance with an outer jacket taining-bead serves 'to prevent rearward displanient or the cylieder. lllleen tools of this typ-e are employed drilling lioles in stone, it is customary to provide e erible bose arranged to conduct e part oi the exhaust to 'the lower end of tbe Workingtool to force the dustroin tbe liolf in practice rnucb diilieult-y is experienced in properly Clearing the liole on account oi tlie varying lengths of tile Working-tools. lin order to accomplish the result desired, tlie end of the liose inust be at the proper distance from the stone.

.The vrorlringtool is dulled quickly, and .lies to be replaced by a sharp onelf TWith the object in vienr of avoiding tlie diliculty above mentioned, l provide means whereby tlie hose can be quickly adjusted for varying lengths of Working-tools, so that the end of the hose will be at the proper distance from the stone. V

lily invention further consists of novel details of construction, all as Will be bereinafter more fully described and pointed out in the claims.

ln the dravvings, lf`igure l is a longitudinal central section on line .1 1 of Fig. l of a tool embodying the invention,fpartly broken away, the valve being in its forward position. F ig. 2 is a longitudinal central section of the valveblock and upper portion of,

the cylinder on line 2 2 of Fig. l, showing a portion of the valve broken away and in its rearward position. F ig. 3 is a section on line 3 3 of Fig. l. Fig. line 4- 1- 'of Fig. l. Fig. 5 is a'ysection on line 5 5 or F ig. l. F ig. 6 is ap elevation showin@ a modification of valve.` Fig. 7 is a detailJ plan of the hose supporter which has a loop through which tl-fe' Work-tool passes. Fig. 8 is a detail vie i on an enlarged scale of a portion or' the valve to .sbovv the charnfered end.

e is aI4 section on* annular groovev 3 in the valve-block.

at tli'e end cia tlie cylinder formed, with a cnain C', a valve l) located and ino/ing in saiochaniber, a head or plate E for tlie cylinder, s retaining-head l?, for tlie valve-block, lvvliicli is in threaded engagement with tlieqaelret A', and a yarn nut G to prevent tbe retainingliead unsorewing from the jacket.. The cylinder A. :is of smaller external diameter at its i'orward end, thereby forming an exhaust Chaniber between said dieineter and the bore of the jacket..

The retaining-lisant is provided with .bore l of dide ent diameters transverse to the' bore of the cylinder, tlie larger diameter bei-n adapted to be connecte-l with a. of fluid pressure supply not shown). sages z, 2', 2, connect lie rear end of the il throttle valve lol is mounted in of the retai ngeliead; the sn y tli valve prog/ents beyond b e engaged by the inclined sin graspingdiandle Said inovably mounted on the retai is retained. thereon by the nipple lirougli which the motive fluid is supplied to the tool. Said nipple .l passes loosely through a hole 5 in tbe side of the grasping-handle. Said hole 5 tion to allow the grasping-handle to inove longitudinallT on tbe retaining-head.

K, K, K2, are springs that normally hold the grasping-handle in a rearward position. The lower ends of said springs are seated in sockets lit, it?, in the bead. The parts are arranged so that the throttle-valve will be moved sullciently to supply Huid to the tool before the grasping-handle reaches the fm'ward liznit of its movement, whereby the relative forward movement oie tbe grasping'- liandle is cushioned by the springs and the j ar and vibration ofY the tool is to a large extent absorbed by the springs Without being transmitted to the hand or the operator.

The part H of the throttle-valve is a close Working i'it in the smallbore of the retaining head to prevent the escape of motive liuid and keep the large end or bead of the valve in alinenient with the bore When the valve is unseated.

il] ien the grasping-handle is pushed forward the inclined surface l moves tlie valve away from its seat, and the motive iiuid passes 'through the passages 2, 9 and 2 to 4the annular 'groove 3 in tbe valve-block.

Tlie valve-bloei: is provided with a passage or series of holes 6 oonnectlng tbe groove 3 with an internal annular groove or inlet-port 'Z Vin the larger bore di the valveblock, and is also provided with anpassage or source llasbore l with an is inade oblong in vertical secseries of' holes S, leading` from the internal annular groove 9 in the valve-block, which register with a passage or series of holes 10 through the plate ll opening into the 'rear end of the piston-chamber. An exhaustport or series of ports 11 eonneets the large bore of the valve-bloek withl the exterior exhaust-groove 12 of' the said block. rlhe retaining-head is provided with an exhaustport 13 which is threaded to reeeive an elbow or connection L to which is'attaehed a flexible hose M.

The groove is connected by a passage or passages 14 in the valve-block and is eonnected by a passage or passages 15 through the plate E with a passage 1G in the wall of the cylinder which opens into the interior of the cylinder through the port 17.

A passage 1S in the wall of' the cylinder provided with two ports 19 and 2() opening into the here of the cylinder. is connected by a passage 2l in the plate E with the' large here of' the valve-block. The passage 22 leads from the t'orward end of the pistoinehamber and Connects with passage 22l in the valve-block. Ports 28, 211, open from passage 22a into the bore of the valve-block. The port 2st is of' larger eapaeity than the port 223, as shown in Fig. 2, the valve being broken away. The port 2l, as shown, is formed by a series of holes and the passage 1l, as shown iii Fig. e, is formed by two-holes, but it will be understood that in each ease a single passage or port of su llieient capacity may be provided.

provided witlran annular groove 20 at its.

laige diameter whieh always open to the exhaust-ports 11 in the valve-block.

When the valve D is 1n a forward position, as shown in Fig. 1, and the graspingi handle is pushed forward, the motive fluid i' will pass around the head of the throttlel l baid passage l The ex- .l haast-ports 11 in the valve-block may he' from the groove 25 in the valve, through port 23 and passage 22n to the 'forward end of the -piston-ehaniber to drive/)the piston rearward. '.lhe forward end of the valve is preferably ehainfeied as shown at 41 in Fig. 8 to allow fluid pressure to pass through port 2l to maintain the valve in its rearward position. lVhen the piston approaches the rear end oli' its stroke the port 2O is uncovered, or opened to the piston-chamber, by the large diameter of the piston and at the saine time the small diameter B oit the pis-' ton passes back out of the small bore of the cylinder, whereby the motive fluid in the .toi-ward end ol theeylinder and valve-chainber will exhaust. through a series of ports 2S in the wall of the cylinder and the ports 21) in the outer jacket A. The area of the ports 2S and 29 is of' much greater capacity than the lport 23 through which the motive fluid is supplied to the forward end of the piston-chamber, and when the said end of the piston-chamber is open to said ports 28 and 29 the pressure is reduced sufficiently to allow the constantly acting pressure on the differential areas of the valve-groove 25 to move the valve forward.

lVhen the piston moving forward, the fluid in front` of the same will pass out through the ports 2S and 29 until the small diameter ol. the piston enters the small bore ot' the cylinder. Then the fluid will pass through the passage 22 to the ports 2st and The fluid from the port 2l passes through the groove 2G in the valve and the ports 11 in the valve-bloel-r to Ythe exhaustport '13. The fluid from the port passes above the rear end of the valveI .to the valvechamber.

l prefer to exhaust the fluid from the rear end of the valve-Chamber through a passage 50 in the retaining-head as shown in Fig. 1 but I may omit said pas ige and exhaust the fluid through the interior of' the valve and a small hole 231 in the. wall of the latter '1 opening into the groove 26 ot the valve as shown in Fig. G.

valve through the passages 2, 2, 2, to the g annular grooie I3, through passages 6 to the inlet-port T, and the annular groove in i the valve. gioove through the passages S and 10 to the rear end of the piston-el-iainher. When the piston is near the forward end of its stroke. the annular groove 2T in the piston g The fluid will pass from said lt is not essential that part of the fluid from the passage 22 he exhausted through the port 23. Said port may he located so that it is not open 4to the valve-chamber when the valve is in its forward position. rlfheexhanst will in that event all pass through port 24. the passage 30. or the hole ill, is to prevent any accumulation of fluid .--pressui'e, which may leak through the joints or bearing surfaces of the valve from aeting against the small diameter or end of the valve.

.W'hen the piston is moving rearward, the fluid from the rear end of the piston-Chanih'er will pass through the passages 10 and S to the annular groove 9, thence' through the groove 26 in the valve and ports 11 in the valvehloek to the exhaust-port 13.

The oh`eet in orovidinv" ioo CII

The cylinder il is provided at its rear end with an external llange A having ports therein which register with grooves cut'in the outside of the cylinder forward of the flange. The outer jacket is forced on the cylinder so that its rear end Will forma duid tight joint with the -torvvard side of the "dange, rihe rearv end ot the jacket is in threaded engagement with the retainingheadxivliich serves to prevent rearward'displacement; or' the cylinder with relation to the jacket.

Tie elbow orconnection Lyis provided with a projection or support 32, as shown in n 3, said support having a bore into which the hose lvl lits snugly so that it will loe-.retained in position and stillgcan he easily drawn tlnfough the support.

The hose is passed through the support in such manner as to term a loop at the rear the-cylinder? and the forward end he hose is provided with a ring or loop secured thereto through which the working-tool passes shown in Zeig. l. wie hose is drawn through the support in .nor the other direction., so that the end `vvill he at the proper distance from the stone Ybeing drilled when Working tools of varying lenfths are employed.

l, 'ln an impact-tool, a piston-chamber and piston, a valve for controlling the move? ments ot' the piston provided with annular groove having opposing pressure surtaccs ot different areas to which the motive duid is constantly admitted to press the valve in one direction, said valve having a pressure surface otstill larger area to which the motive ,luid is intermittently admitted to more the valve in the opposite direct-ion, an

i external annular' groove in the larger diameter of the valve and communication hetween said groove and the atmosphere e2;- ternally to the valve which is constantly open.

2. ln an impact-tool, a piston-chamber and piston, a valve :tor controlling the movements oi" the piston having an external annular groove whiclris always incommunication with the atmosphere externally to the valve7 said va c seing provided With an annular groove naving opposing pressure surfaces oi, areas to which the motive duid' is constantly admitted to press the valve one direction and a pressure surface ot sti. rger area to which the mot-ive fluid is intermittently admitted to move the valve in the opposite direction, said valve having one end constantly open to the atmosphere.

ln an impact-tool, a piston-chamber and piston, ya valve of diltcrent diameters for controlling the movements of the piston consisting or' a tuhular'shell l aving its interior sur- `tace always open to the atmosphere and provided ivith'opposing pressure ,surfaces 'of Jnt areas to which the motive duid is constantly admitted to press the valve in one groove and the atmosphere externally to the valve which is constantly open.

il. ln an impact-tool, a piston-chamber and piston, a valve for controlling the moveJr ments of the piston consisting of a tubular shell having its interior surface always open to the atmosphere, said valve having tWo annular grooves, to one of which themotive duid is constantly admitted and the other of said grooves having communication With the atmosphere externally to said valve which is constantly open. n

5. in duid controlled impact-tool, a piston-chamber and piston, a valve provided with opposing pressure surfaces against which the motive 'fluid acts to move the valve in opposite directions, valve-block having an inlet-port transverse to the bore of the bloclr and to which the motive duid is constantly admitted7 eXhaust;ports in the valveoloclr which are always open to the atmosphere, said valve being provided with tWo annular grooves7 one of said grooves beingv always open to said inlet-port in the valvebloclr andthe other of said grooves 1losing' al- Ways open to said exhaust-ports in the valvelolocl-f. l

6. ln a fluid controlled impact-tool, a piston-chamber and piston a valve provided With opposing pressure surfaces against Which the motive fluid acts to' move the valve in opposite direct-ions. a valve-block having an annular inlet-port to Which the mot-ive fluid is constantly admitted, exhaust-ports in the valve-block which are alwaysopen to the atmospherd said valve being provided with two annular grooves, one of said `grooves being always open to said annular inlet-port in the valve-block and the other o said grooves being always' open to said eX- 'haust -ports in the valve-block,v said valveblock having ports and passages connected respectively With opposite ends vof the piston-chamber and adapted to be brought al- A tern-ately into communication with said infl let-port and exhaust-ports by the reciprocation ot' said valve. l

7. l'n a fluid controlled 'impact-tool.,` a valve-block having an inlet-port and exhaust-ports, said exhaust-ports being always open to the atmosphere, a` valve located in said valve-block provided With an annular groove having pressure surfaces of dierent areas to which the motive duid is constantly admitted through said inlet-port' to press the valve in one direction 'and an annular groove which is always open to said exhaust-ports in the valve-hlock, said 'alve being provided with a presstre surt'aee ot still larger area to which the motive tluid is intermittently admitted to move the valve iu the opposite direction. A

8. In a fluid controlled impact-toolA` a valve-block having a tubular valve therein, the interior ot said valve being always open to the at'mosphere.y said valve-hltufk being provided with exhauselmrts which are always open to the atmosphere. an annular groove in the valve to which the .motive fluid is constantl) supplied tlnotigh an inlet-port in the valve-block and an annular groove in the valve which is always: open to said eX- haust-ports in the valve-blockr` said valve being provided with opposing pressure suritaces to which the motive lluid admitted to shift the valve in opposite directions.

tl. .ln a fluid controlled impact-tool, a valve-hlocli.having a here ot dill'erent diametersT the smaller horel heing always open to the atmosphere. eXltaust-ports in said valve-block opt-ning into the bore otl larger diameter` a valve located in the valve-block' provided with opposingV pressure surfaces of ditlerent areas to which the motivo lluid is constantly admitted to press the valve in one direction and an annular `groove which is alwa v:-y open to said exhaust-ports, said valve heilig provided with a pressure surface ot' still larger area to which the motive fluid intermitttmtlv admitted to move the valve/5in an opposite direction.

1t). ln a tluid controlled impact-tool7 a piston-chamher and piston` a valve-block having an interior annular inlet-port to ,which the motive lluid is constantly admitted and an interior annular groove, connected h v ports and passages to one end of the pistolifchamher` exhaust-ports in the valveblock` ports' in the valve-hlocl; in proximity to opposite endsI ot the valve-chatnhei` and etaiueeled hy passages with the opposite end ot the pistonhamher, a valve lor controlv ling the movtmientis ot the piston, said valve being provided with two annular grooves, one of said grooves4 heing always,l open to tluid pressure and the other' groove always open to said exhaust-ports` the ports connected respectively with the passages' leading Jfrom opposite ends ot' the piston-chamber being adapted lo he hrought alternately into communication with .said inlet-port and exhaustports h v the reciprt'ication o't` the valve.

11. In a [luid controlled impact-tool, a piston-chamber and pistou. a valve block provided with an interior annular inlet-port or groove to which the motive fluid is constantly admitted, exhaust-ports in the side walls of.' the valve-block, a valve adapted to control the admission ott motive fluid to opposite endey o'tl the pistoirchamher and provided with two annular grooves, one of said grooves'heiug loeated in the small diameter of the valve and always open to said inletport m the valve-hloclr. and the other of said `groovesI being located in the large diameter ol" the valvewatul adapted to be alternately placed in communication with passages 'leading respectively to opposite ends`A ot the pistou-elnnuher and always open lo said exhaust-ports externally lo the valve.

1;. In a tluid controlled impact-tool, a valve-hloek aaviug a here of di'tlerent diameters, the .smaller here being always open to the atmosphere. said valve-block being providedwith aninterior annular inlet-port to which the motive fluid is constantly admiti ed and with exhausbports always open to the atmosphere, a valve in said valvehlocl: provided with two annular grooves, one of said grooves heilig always open to said interior inlet port in the valve-blocki and the other ot' said grooves being always open to said exhaust-pints.

121. In a fluid controlled impact-tool, a piston-chamber and piston. a valve-block provided with an inlet-port to which the mo tive fluid is constantly admitted and with ex- ,haustports which are always open to the atmosphere, a valve for controlling the movements of the piston provided with au annular groove having opposing pressure surfaces o't' ditt'crent areas against which the motive tiuid constantly acts` to press the valve in one direction4` and au annular groove which always open to said exhaust-ports, said valve being` provided with a pressure surface of still larger area against which the motive fluid acts to move the valve in an opposite direction.

le?. ln .a fluid controlled impact-tool, a piston-chaml'ier and piston, a valve-block provided with an annular inlet-port to which the motive fluid is constantl.,v admitted and with exhaust-ports in the side walls thereof which are always open to the atn'iosphere`r a valve ot ditferent diameters adapted to control the admission and exhaust ol motive tluid to and from opposite ends of the piston-chamber. said valve being provided with au. annular groove which is always ope-n t-o said annular inlet-port and an annular groove in the large diameter ot' the valve adapted to he alternately placed in communieatiim ith passages ladiug respectively to opposite ends ot the piston-chamber, said groove he'ing always open to said exhaustiportsI exteruallv to the valve.

l5. ln a fluid controlled impact-tool, a piston-ehamher and piston, a valve-block provided with an inlet-port to which the inotivo fluid is constantly admitted and with exhaust-ports in the Side wallsI thereof which are always open to the atmosphere, a valve t'or controlling the movements of the piston, said valve consisting of a tubular shell of interior sur'taee always open to the atmosi en' inlet-port the velvebloclr loeeteol forward of inpectatool,

seid ennulor recess end connected by pessngcs therewith, Jhe smaller. diameter oit seid bore l eing always open to i etnospliere, s head for the'velve-bloclr Toro" -ded with e bore transverse to the bore.

the valve-bloei?. to which the motive rluid is constantly admitted, seid bore of .the head1 connected vvith passages vvhichregisith seid recess in the valve-bloei; Wheree motive iuid is supplied-to seid inlet-f.

ln s fluid controlled inipect-tool,e 'valve-bloc; having e bore oit dirllerent diameters, the sinsller bore et its end being always open to the atmosphere exhaust-port rearward or" and anterior to the valve-block, en inletport. opening into the ger bore and conneeted by passages with annuler rec-ess'in the valve-block to which motive iluid is constantly nitted, seid recess encircling the snisll bore of the valveblocl rearward of sold inlet-port.

l. ln nneuinetic impact-tool, n cylinder having e A'"e et its rear end end provided externally itplongitudinel grooves connected'by port-holes with the interior of the cylinder, said lieving port-lioles therein which register respectively Withseid grooves, seid cylinder being provided with outer joe ret, seid acl-ret being engaged at its rear end by seid ilenge to prevent for? Ward displacement of the cylinder With Vrelation to the jacket.

i9. ln pneumatic impact-tool, e cylinder having e flange et its rear end and provided externally With longitudine-l grooves connected by port-holes with the interior of the cylinder, seid ilenge having port-holes therein which register respectively with said grooves, seid cylinder being provided With en outer jacket (2f-greater length than the cylinder, seid jacket being engaged et its rear end by seid flange, seid cylinder having e. portion or smaller diameter at its forward end and provided with a series of holes through the Wells et seid forward end, seid jacket. having eseries of holes opening into the space between seid smaller end of the cylinder and the bore of the jacket.

20. ln n impact-toons piston-chamber end piston, e valve-block provided with exhaust-ports in the side Wells thereof, and with ports end passages leading respectively opposite ends ,of 'the piston-chamber, e

'Q inoveinents of the d by the piston for 1 g actuating the velve, seid valve-being. provided `with two annuler grooves, one ol sind grooves .being always open to fluid "pressure,- y

the other of seid' grooves being always open to seid eilianstports end adapted by the shitting' of the valve to alternately connect seid exhaust-,ports externally to the valve, with opposite ends o? the piston-chamber.

:21. en impact-tool, a piston-chamber end piston, e, valvebloclr provided with eX- lienst-norts in the side 1mills thereof end with ports and passages leading respectively `f ."oe ulternetely connected with opposite ends )ofc the piston-chainber, the other of said grooves being always open to said exhaust? ports and adapted' by the shifting o'if the valve to'elternstely 'connect seid exhaustports, eltternelly to the valve, with opposite ends oit the piston-chamber. l, r 22; 'ln an impact-tool, a piston-chamber i piston, e valve-block provided with exsports in the side Walls thereof, an in- 'port in the valve-block .to which the ino- .uid constantly admitted, e valve for controlling the movements of the piston provided Withtvvo annuler grooves, one of said grooves being'elw'ys open to, seid inlet-port, the other of seid groves being elvoys open vto ssid'exhaust-ports' externally to the valve, seid valve-bloclr having ports and passages connected respectively With opposite ends of the piston-cha1nber *which are adapted to be brought elternctelyby the shifting of the valve into communication with seid inletport fend with seid eXhaust-ports- 23. ln en impact-tool, e pistoncliamber and pistoina volvo-block provided With eX heust-ports in the side Walls thereof, an inlet-port in the valve-block to which the motive fluid is constantly admitted, e valve lorv controlling the movements of 'the piston provided with two annular grooves, one of seid. grooves beingelwnys open to said inletport, the other oit seid grooves bein "always open to said'eXheust-ports external?! toA the valve, an `annular groove in the valve-block connected by passages to one end of the piston-chamber, e passage leading from the 0pposite end of the piston-chamber provided with tvv'o ports, one of said ports being controlled by the velveto admit motive fluid to said opposite end ot' the piston-chamber and the other of said ports being controlled by the valve to exhaust Huid from said opposite end of the piston-chamber.

and nis.' valve-block provided with on ton, inletpert en impect-tool, e piston-chamber' nnverse to the bore oit the block 5' -to which the motive fluid is constantly admitted and with exhaust-ports which are always open to the atmosphere, a valve t'or controlling the movements ot' the piston provided with Opposing pressure surfaces of ditlerent areas and an external annular groove which is always open to said inletport and an external annular groove whichis always open to said exhaust-ports externally to the valve, an annular groove in the valvebloek connected by passages-to one end of the piston-chamber7 a passage leading trom the opposite end of the piston-chamber provided with two ports opening into the bore of the valve-block, one of said ports being controlled by the valve to admit motive fluid to the opposite end of the piston-chamber and the other ot' said ports being controlled by the valve to exhaust lluid from said opposite end of the piston-chamber.

25. In an impact-tool, a piston-chamber and pist-on, a valve-block having a bore in alinement with the bore oi the piston-chamer and provided with an inlet-port to which the motive tluid is constantly admitted, exhaust-ports in the valve-block located lorward of said inlet-port, a valve provided with an annular' groove which is always open to said inlet-port externally to the valve and an annular groove which is always open to said exhaust-ports externally to the valve and an interior annular groove in the valveblock located forward ot' said inlet-port which is connected by passages with one end ot the piston-ehan'iber.

:26. In a pneumatic impact-tool, a pistonchamber and piston, a valve-block, a valve for controlling the movements of the piston provided with an external annular groove to which the motive fluid is constantly admitted, and an external annular groove which is always in communication with the atmosphere externally to the valve, a port in the valve-block connected by passages with one end of the pistoil-chamber,y a passage leading from the opposite 'end ot' the pistonchamber provided with two ports opening into the bore of the valve-block, one of said last mentioned ports bei-ng controlled by the valve to admit motive fluid to said opposite end ot' the piston-chamber, and the other ot said ports being controlled by the. valve to exhaust fluid from said opposite end of the piston-chamber.

27, ln a pneumatic impact-tool, a pistonchamber and piston, a valve-block, a valve for controlling the movements of the piston provided with an external annular groove to which the motive fluid is constantly admitted, and an external annular groove which is always in communication with the atn'iosphcre externally to `the valve` a port in the valve-block connected by passages with 011e end ot' the piston-chamber, a passage leading 'from the opposite end of the pistonchamber provided with two ports opening into the bore of the valve-block, one of said last mentioned ports being controlled by the valve to admit and exhaust motive fluid to and from said opposite end ot' the pistonchamber`r and the other of said ports being controlled byv the valve to exhaust fluid Jfrom said opposite end ol. the piston-chamber.

ln an impact-toolv` a piston-chamber and piston. a valve-block provided with exhaust-ports in the side walls thereof; an inlet-port in the valve-block to which the motive fluid is constantly admitted, a valve t'or controlling the movements of the piston provided with two annular grooves, one ot' said grooves being always open to said inlet-port, the other of said grooves being always open to said exhaust-ports externally to the valve, a port in the valve-block connected by passages with the rear end ot' the piston-chamber, a passage leading trom the iiorward end of the piston-chain- `ber provided with two ports7 one 0f said ports being controlled by the valve to admit motive tluid to the forward end of the piston-chambe f and the other ot' said ports being controlled by the valve to exhaust tlnid trom the forward end ot' the pistonchamber.

J. In a pneumatic impact-tool, a pistonchamber and piston, a valve-block, a valve tor controlling the movements of the piston provided with an external annular groove to which the motive fluid is constantly admitted. and an external annular groove which is always in connnnnication with the atmosphere externally to the valve, a port in the valve-block connected by passages with one end ot the piston-chamber, a passage lead- -ing from the opposite end of the pistonchamber provided with two ports opening into the bore ot' the valve-block, one of said' last mentioned ports being` controlled by the valve to admit motive fluid to said opposite end oit the piston-chamber. and through the other ot` said last mentioned ports to one end ot' the valve to retain it in the proper position when the motive tluid is supplied to said opposite end ol the piston-chamber.

llt). In an impact-tool, a solid valve-block having a bore of ditl'crent diameters` the smaller bore being always open to the atmosphere. an interior annular inlet-port in thc valve-block connected by passages in tht` block with an annular groove in the rear end ot the 'valve-block to which the motive tluid is constantly admitted7 said groove encircling the small bore ot the falve-blocl: forward of its rear end.

3l, In an impact-tool, a piston-chamber and piston, ay valve-block provided with' exhaust-ports in the side walls thereof, anv inlet-port in the valve-block to which the motive tluid is constantly admitted, a valve for 'controllingl the movements ot the piston providediwith two annular grooves, one of said grooves being always open to said inletport, the other of said grooves being always open to said exhaust-ports externally to the valve, a passage leading Atrom one end of the piston-chamber to a port in the valve-block, said port being-controlled hy the valve to admit motive r'luid to and exhaust fluid from said 'end of the piston-ohamherj'a port in the valve-bloei: connected hy passages with the opposite'end of the piston-chamber, said port being vcontrolled by the valve to admit and exhaust mot-ive fluid to and from the vsaid opposite end of the piston-chamhen 32. ln an' impact-tool, a piston-chamber and piston, a valve-block provided With eX- haust-ports in the side Walls thereof, an inlet-port in the valve-hloclrtto which the motive duid is constantly admitted, a valve for controlling the movements of the piston provided With tivo annular grooves, one or' said grooves being always open to seid inletport, the other of said grooves being always open to said exhaust-ports externally to the valve, a passage leading from the forward end of the pistou-chamber to a port in the valve-lolocli2 said port being controlled by the valve to admit motive'iluid to said for- Ward end of the piston-chamber and a port controlled by the valve adapted to admit motive Huid from said passage to one end of the valve to retain the latter in position.

ln an impact-toch a piston-chamber and piston, a valve-bloot: nrovided with cxhaust-ports Qin the side l thereof, an inlet-port in the valv lilo' t which the motive liuid is consta nitted, a valve for controlling the movements or the pistou orovided with two annular grooves, one of .said grooves being always open to said inlet-port, the other of said grooves being` always open to said exhaust-ports externally to the valve, said l mentioned groove being' adapted 185i', by the shifting of the valve to alternately exhaust the motiveV fluid from opposite ends of the piston-chamber, and means controlled by 'the piston whereby the valve may he moved to alternately admit motive liuid to opposite ends or" the piston-chamber.

l'n duid operated impact-tool, a valve orovided with an annular groove to which the motive fluid is constantly sup- Y plied externally to the valve, and an annule groove which is constantly open to the atmosphere externally to the valve, said grooves acting in either position of the valve to supply motive iiuid to one end of the pistonchamher and to exhaust Huid from the respective opposite end of theVpiston-chan'iher. in a -iuid operated impacttool, a valve-clock provided with an inlet-port, and with ports communicating respectively With opposite endsor fthe cylinder; adjacent' to sortes? and ou opposite sides of the inlet-port and further provided With exhaust-ports adjacent to the said cylinder ports, a, valve provided with opposing pressure surfaces of different `areas against which the motive fluid acts to move the valve in opposite directions and having an annular groove'wvhich is constantly open to saidinlet-port, and through which motive fluid is alternately supplied to opposite ends hf the cylinder by the reciprocations oi the valve7 said valve having` hearing sui1M faces on either side of said groove which tend to prevent the motive fluid passing 'from the groove to the atmosphere and of such length that when the valve is in position to supply motive fluid to one end of the cylinder, the port leading to the respective opposite end of the cylinder is in communication ywith the exhaust ports adjacent thereto.

36. ln a fluid operated impact-tool, a valve-block orovided with an inlet-port, and with ports communicating respectively With opposite ends of tie cylinder, adjacent to and on opposite sides of the inlet-port and further provided with exhaust ports adjacent to the said cylinder ports, a valve provided with opposing pressure surfaces of diiderent areas against which the motive iluid' acts to move the valve in opposite directions and having an annular groove which is constantlyT open to said inlet port, and through which motive fluid is alternately supplied to opposite ends of the cylinder hy the reciprocation of the valve, said valve having,r hearing suriaces on either side of said groove which tend to prevent the motive 'duid passing from the groove to the atmosphere and of such length that when the valve is in position to supply motive luid to one end of the cylinder, the port leading to the/respective opposite end o'f the cylinder is in communication with the exhaust ports adjacent thereto and the respective opposite exhaust ports are not covered or sealed hy the hearing surface of the valve a 37. ln a v'duid operated impact tool, a valve-block provided with an inlet port, and

`with ports comnninicatingrespectively with opposite ends or' the cylinder, adjacent to and on opposite sides of the inlet port, and further provided with exhaust ports adjacent .to the said cylinder ports, a valve provided Withopposing pressure surfaces of diiiferent areas against which the motive iiuid acts to 'move the valve in opposite directions and having projections with hearing` surfaces which pass over said cylinder ports during,- the travel of the valve and in the opposite positions of the valve `present opposite sides of the projections to the said 'cylinder ports `'permitting alternated" the admission o1?. mo-

tive luid to and the exhaust et fluid from respective ends ofthe cylinder.

move the valve in opposite directions and -having projections with bearing surfaces which pass over said cylinder ports during the travel of the valve and in the opposite positions of the valve present opposite sides of the projections to the said cylinder orts permitting alternately the admission o motive fluid to and the exhaust of fluid from respective ends of the cylinder, said bearing surfaces tending when in either position to prevent the escape of motive fluid from the inlet port to the atmosphere.

.39. In a fluid operated im act tool, a valfle-block provided with'an in et port, and Wit opposite ends of the cylin er,adjacent to and on opposite sides ofthe inlet port, and further provided with exhaust ports adjacent to the said cylinder ports, a valve provided with opposing pressure surfaces of dierent areas against whichvthe motive fluid acts to move the valve in opposite directions and having bearing surfaces which in its opposite positions tend to prevent the escape of motive fluid from the inlet port to the atmosphere, permitting alternately the admission of motive fluid to and the exhaust from respective ends of the cylinder, said bearing surfaces not covering or sealing the exhaust ports to the atmosphere.

40. In al fluid operated impact-tool, a valve provided with an annular groove to which the motive fluid is constantly supplied externally to the valve and a. pressure surface constantly subject to fluid pressure tending to ypress the valve in one direction, and a larger pressure surface to which motive fluid is intermittently admitted to move the valve in the opposite direction, and an annular groove which is constantly open to the atmosphere externally to the valve, said grooves acting in either osition of the valve to supply motive flui to one end of the pistonchamber and to'exhaust fluid from the respective opposite end of the piston-chamber.

4l. In a fluid operated impacttool, a valve-block provided with an inlet-port, and with ports communicating respectivelywith opposite ends of the cylinder, adjacent to and on opposite sides of the inlet-port, and further provided with exhaust ports adjacent to the said cylinder ports, a valve having an annular groove which is constantly open to said inlet-port and a pressure surface constantly Orts communicatin respectively with,

subject to fluid pressure tending to press the valve in one direction and a larger pressure surface to which the motive fluid is intermittently admitted to move the valve in the opposite direction, thc motive fluid being supplied through said groove alternately to opposite ends of the cylinder by the reciprocations of the valve, said valve having bearing surfaces on either side of said groove which tend to prevent the motive fluid passing from the groove to the atmosphere and of such length that when the valve is in position to supply motive fluid to one end of the cylinder, the port leading to the respective opposite end of the cylinder is in communication with the exhaust ports adj'acentfthereto.

42. In a fluid operated impact tool, a

r-valve-block provided with an inlet-port and with ports communicating respectively with opposite ends of the cylinder which are located adjacent to and on opposite sides of said inlet-port, a' valve provided with opposing pressure surfaces .of different areas against which the motive fluid acts to move the valve in opposite directions and havingan annular groove which is always subject to uidpressure and which'connects the inletport .alternately with theiports leading to opposite ends of the cylinder, exhaust-ports in the valve-block adjacent to each of said last mentioned ports and in communication with one of said ports when the groove in the valve is in communication with the other of said ports.

'43. In a fluid operated impact-tool, a valve having a pressure surface constantly subject to fluid pressure tending to press the valve in .one direction and a larger pressure area to which the motive fluid 1s intermittently admitted to move the valve in the opposite direction, a valve-block provided with an inletport and with ports communicating respectively with opposite ends of the cylinder which are adjacent to and on opposite sides of the inlet-port, said valve having an annular groove which is always subject to fluid pressure and which connects the inlet-port alternately with the ports leading respectively `to opposite ends of the cylinder, exhaustports 1n the valve-block adjacent to each of said last mentioned orts and in communication with one of sai ports when the groove in the valve is in communication with the otherof said ports.`

'44. In an impact-tool, a valve havin an' annular groove to which the motive flu1d is constantly supplied and an annular groove which is always open to the atmosphere eX- ternally to the valve., a. valve-block having a port comrminicatinnv with one end of the cylinder and located between an inlet-port and an exhaust-port in the valve-block antLalternately placed in communicationtherewith by the reciprocations of the Valve whereby mo- Ative fluid ,is supplied to and exhausted from the cylinder through said port, said valveblock havin a port communicatingwith the opposite eng of the cylinder which is located between inlet and exhaust-ports in the valveblock and alternately placed in communication therewith by said annular grooves in the valve.

45. In an impact-tool, a valve having an annular groove to which the motive uid is constantly supplied and an annular groove which is always open to the atmosphere externally to the valve, a valve-blo`ck having a port communicatin with the forward end of the cylinder and cated between an inletport. and an exhaust-pont in the valve-block and alternately placed in communication therewith by the reciprocations of the valve whereby motive fluid is supplied to and exhausted from the cylinder through said port, said valve-block having a port communicatin with the rear end of'the cylinder which is ocated between inlet and exhaust-ports in the valve-block and alternately laced in communication therewith by sai annular grooves in the valve. l

46. In an impact-tool, a valve of different diameters having a pressure surface to which motive fluid is constantly admitted tending to press the valve in one direction, a larger pressure surface to which motive fluid is intermittently admitted to move the valve in the opposite direction, and an area equal to the difference in area between said pressure surfaces which is always in communication with the atmosphere to prevent any accumulation of pressure thereon acting in opposition to said larger area, said valve having` an annular groove to which motive fluid is always supplied and another annular groove Awhich is always open to the atmosphere externally to the valve.

47. In an impact tool, a piston chamber and piston, a valve for controlling the movements of the piston provided with an annular groove having opposing pressure surfaces of diierent areas to which the motive fluid is constantly admitted to press the valve in one direction, said valve having a pressure surface of still larger area to which the motive fluid is intermittently admitted to move the valve in the opposite direction, an external annulargroove in the -larger diameter of the valve, and communication between said groove and the atmosphere externally to the valve.

48. In an impact tool a piston chamber and piston, a valve block, a valve for controlling the movements of the piston provided with an .a nnular groove having opposingpressure surfaces of different areas, an annular groove in the valve block communicatcease? ing at all times with the said valve groove, a passage connecting the groove of the valve block with a source of pressure supply, said valve having an external annular groove in its larger diameterand an exhaust vport adapted to coperate with said groove.

49. In anv impact tool a piston chamber and piston, a valve block, a valve for controlling the movements of the piston provided with an annular groove having opposing surfaces of di'erent areas, an annular groove in the valve block communicating at all times with the said valve groove,

of the valve block, an annular groove in the larger diameter of the valve, an exhaust port, and a cylinder port between the exhaust and inlet ports said cylinder port communicating with the cylinder by one or more longitudinal passages.

50. In a fluid operated impact tool a c linder chamber, a valve block havinga va ve chamber at the rear of the cylinder chamber, an Ainlet port, a longitudinal passage leading rearwardly from the inlet port to a source of pressure supply, a cylinder port, a vlongitudinal passage leading forwardly from the cylinder port to the rear end of the cylinder, a valve provided with an annular groove constantly in communication with the inlet port, and an annular groove constantly open to the atmosphere, said groove in either position of the valve acting tob supply motive fluidl to one end of the piston chamber and to exhaust fluid from the respective opposite end of the piston chamber.

51. In a fluid controlled impact tool a valve block having a bore of different diamethe atmosphere, an exhaust port in the valve block opening into the bore of larger diameter, a valve located in the valve block provided with opposing pressure surfaces of different areas to one of which motive fluid is constantly admitted to .press the valve in sure is intermittently admitted to press the valve in the opposite direction, an inlet port transverse to the bore of the valve Qlock, a cylinder port also transverse thereto, a longitudinal passage extending in one direction from the inlet port and communicating with the source of pressure supply, and a longitudinal passage extending in theopposite dimunicating with one fend of the cylinder.

52. In a fluid-controlled impact-tonol, a piston-chamber and piston, a valve provided with opposing pressure surfaces against which the motive fluid acts to move the valve in opposite directions, a valvefblock having an inletort transverse to the bore ters, the smaller bore being always open to one direction, and to the other of which pres-A rection from the cylinder port and com-- one or more longitudinal passages extending from said valve groove to the adjacent end' of the block and to which the motive fluid lll is constantly admitted, an exhaust-port in the valve-block always open to the atmosphere, said valve being provided with two annular grooves, one of said grooves being always open to said inlet-port in the valveblocl and the other of'said grooves being always open to said exhaust-port in the valve-block and acting to exhaust mot-ive fluid from both ends of the cylinder.

53. In an impact-tool, a piston-chamber and piston, a valve-block having a bore in' alinement with the bore of the piston-chamber and provided with an inlet-port to whichA the motive fluid is constantly admitted, an exhaust-port in the valve-block located forward of said inlet-port, a valve provided with an annular groove which is always open to said linlet-port externally to the valve and and annular groove which is always open to said exhaust-port externally of' the valve, the latter groove acting to exhaust motive fluid from both ends of the cylinder,

, and an interior annular groove in the valveblock located forward of said inlet-port which is connected by passages with one end of the piston-chamber.

54. In an impact-tool, 'la piston-chamber and piston, a valve-block provided with an exhaust-port in the side wall thereof, an inlet-port in the valve-block to which the motive fluid is constantly admitted, a valve for controlling the movements of the piston provided with two annular grooves, one of said groovesbeing always open to said inletport, the other of said grooves being always open to said exhaust-port externally to the valve and acting to exhaust motive fluid from both ends of the cylinder, a passage leading from one end of the piston-chamber te a port in the valve-block, said port being controlled by the val-ve to admit motive fluid to and exhaustfluid from said end of the piston-chamber, a port in the valve-block connected by passages with the opposite end of the piston-chamber, said port being controlled by the valve to admit and exhaust motive fluid to and from the said opposite end of the piston-chamber.

155.1n a fluid operated impact tool, a

valve-block provided Withan inlet port, and

with ports communicating respectively with opposite ends of the cylinder, and`further provided with an exhaust port adjacent to the said cylinder ports, a valve having an annular groove constantly open to the exhaust and acting to exhaust motive fluid from both ends of the cylinder, and an annular groove which is constantly open to saidinlet-port, a pressuresurfaee constantly subject. to fluid pressiu'e tending to press the valve in one direction and a larger pressure surfaceto Which the motive fluid is vinterlil.

mittently admitted to move the valve in the opposite direction, the motive fluid being supplied through said latter groove alternately to opposite ends of the cylinder by the reciproeations of the valve, said valve having bearing surfaces on' either'` side of said roove which tend to prevent the motive luid passing from the groove to the atmosphere and of such length that when the valve is vin position to supply motive fluid to one end of' the cylinder, the port leading to the respective opposite end of the cylinder is in communication with the said exhaust port.

56. In an impact-tool, a valve havin an annular groove to which the motive fluid is constantly supplied and an annular groove which is always open to the atmosphere eX- ternally 'te the valve and yacts to exhaust motive fluid from bothends of the cylinder, a. valve-block having a port communicating with one end of' the cylinder and located between an inlet-port and an exhaust-port in the valve-block and alternately placed in communication therewith bythe reciprocations of the valve whereby motive fluid is supplied to and exhausted from the cylinder through said port, said valve-block having a port comnmnicating with the opposite end of the cylinder which is located between inlet and exhaust ports in the valve-block and alternately placed in communication therewith by said annular grooves in the valve.

57. In an impact-tool', a valve having an annular groove to which the motive fluid is constantly supplied and an annular groove which is always open to the atmosphere externally to the valve and acts to exhaust pressure alternately from both ends of the cylinder, a valve-block having a portcommunicating with the forward end of the cylinder and located between an inlet-port and an exhaust-port in the valve-block and alternately placed in communication therewith by the reciprocations of the valve whereby motive fluid is supplied to and 4exhausted from the cylinder through said port, said valve-block having a port communicating with the rear end of the cylinder .which is located between inlet and exhaust-ports in the valve-block and alternately placed in communication therewith by said annular grooves in the valve.

58. In a pneumatic impact tool a piston chamber and piston, a valve chamber and a differential pressure actuated valve therein, a pair of circumferential grooves on said valve, an inlet port in constant` communica- Vtion with. one groove, an exhaust port in con- I on the opposite side of the inlet port from municating with the opposite end of the sure from the opposite Cylinder end through Cylinder and opening into the valve chamber both of said port openings. 10

In testimony whereof I affix my signature, in presence of two Witnesses.

GERGE L. BADGER. Witnesses THOMAS F. MCANARNEY, l CHARLES H. MGANARNEY.

the first-named cylinder port, the opposite cylinder end also having afport opening into the Valve chamber on the opposite side of the exhaust portfrorn the icrst named cylinder port, and means for exhausting pres- 

